Basically we want the home hub in the front room but the phone socket is on the stairs is there some sort of extension we can have that will not slow or effect speeds at all?
it is best to leave the modem beside the phone socket if possible and run a cat5e or cat6 ethernet cable from the modem to where ever you want to put the homehub, this should not have any effect on your speeds
Yes, an ethernet cable is reckoned to be good for 100m without significant loss. If you have a HH5 though, it will have to be a longer data cable, which is good for 30m.
My phone socket is by the front door & my modem is in my upstairs study.
I've used about 17m of copper cat5e cable to do the extension & that has not contributed to any loss whatsoever as checked by an OpenReach broadband engineer.